Quantum transport simulations of BDT and CuPc and Bayesian parametric analytic continuation
Michael Rumetshofer
Institute of Theoretical and Computational Physics
09:50 - 10:30 Friday 10 May 2019 HS P3 (PH02112)

We investigate the equilibrium and transport properties of benzenedithiolate (BDT) between monoatomic Au and Pt electrodes [1] and a copper phthalocyanine (CuPc) molecule adsorbed on Au(111) and Ag(111) surfaces [2]. Starting from density functional theory calculations, we use a projection scheme to obtain an Anderson impurity model (AIM) accounting for strong electronic correlations. To solve this AIM we can use several methods, e.g. the recently developed fork tensor product state (FTPS) solver [3] or a continuous-time quantum Monte Carlo (CTQMC) solver. For CuPc on Ag(111) we employed the FTPS solver that shows a generalized Kondo scenario with a symmetry between SU(2) and SU(4).

In this talk, I am going to sketch the calculation scheme for molecular quantum transport including strongly correlated orbitals and I will present results concerning BDT between monoatomic Au and Pt electrodes and CuPc on Au(111) and Ag(111). Additionally, I will introduce Bayesian parametric analytic continuation (BPAC), a method for the analytic continuation of noisy imaginary-time Green’s function data, e.g. as obtained by CTQMC. Compared to the maximum entropy method, routinely used for the analytic continuation of CTQMC data, the presented approach allows to ask whether the data supports specific structures of the spectral function. We successfully applied CTQMC and BPAC to an AIM similar to that of CuPc on Ag(111).

[1] M. Rumetshofer, G. Dorn, L. Boeri, E. Arrigoni, and W. von der Linden, New J. Phys. 19, 103007 (2017).
[2] M. Rumetshofer, D. Bauernfeind, E. Arrigoni, and W. von der Linden, Phys. Rev. B 99, 045148 (2019).
[3] D. Bauernfeind, M. Zingl, R. Triebl, M. Aichhorn, and H. G. Evertz, Phys. Rev. X 7, 031013 (2017).